1. Field of the Invention
The present invention relates to a wireless receiver device for wirelessly receiving audio signals from a remote source, which is capable of supplying such audio signal to a hearing instrument. The invention also relates to a hearing instrument which is capable of wirelessly receiving audio signals from a remote source.
2. Description of Related Art
It is well-known to use a receiver device (usually an FM (frequency modulation) receiver) for receiving audio signals from a remote source, for example a remote microphone, via a wireless link (usually an FM link) in order to provide such audio signals as input signals to a hearing instrument worn at a user's ear. To this end the receiver device has an output interface which is capable of being mechanically connected to an input interface of the hearing instrument via a so-called “audio shoe”. The audio shoe is mechanically connected to the input interface of the hearing aid and comprises typically a standardized 3-pin socket for receiving three mating pins of the output interface of the receiver device, which pins typically are arranged in a line. However, the orientation of the three pins in the audio shoe with respect to the hearing instrument, i.e. with respect to the user's head, is not standardized and therefore varies from type to type. Moreover, the sensitivity of the antenna of the receiver device depends on the relative orientation to the user's head, with the optimum orientation of the antenna being given if the loop surface is perpendicular to the direction of the user's nose. If the receiver device is turned by 90°, the loss in sensitivity is typically of the order of 6 dB.
A presently used solution to this problem is to provide for a mechanical construction which allows to orient the receiver device in the optimum direction for all types of hearing instruments, wherein the connector, i.e. the mechanical components of the output interface of the receiver unit (i.e. the three pins), is rotatable with respect to the housing of the receiver device, so that prior to plugging the receiver unit into the audio shoe the connector can be rotated in an appropriate manner so as to adapt the orientation of the receiver device to the specific type of audio shoe/hearing instrument. Such receiver devices are sold, for example, by Phonak Communications AG, Murten, Switzerland, under the product designation MLx S.
A drawback of this solution is that a rotatable connector results in larger dimensions of the receiver device, given by the space required to design and implement a reliable and stable mechanical solution for the connector rotation. In addition, the electrical connections between the connector and the electronic module of the receiver device need to be flexible in order to allow the rotation of the connector with respect to the electronic module, which results in additional complexity, e.g. soldered wires, and again larger geometrical dimensions. A further drawback is the need to instruct the user regarding how to manipulate the receiver device, i.e. how to rotate the connector, on all sorts and types of combinations of hearing instruments and audio shoes.
European Patent Application EP 1 531 649 A2 describes a wireless hearing aid system with a magnetic loop antenna on a flex print, wherein at least a portion of the matching network is affixed to the flexible dielectric substrate carrying the antenna. The antenna may be attached to the inner or outer surface of the shell of the hearing aid, with the shape of the loop antenna being matched to the irregular shape of the hearing aid shell.
German Patent Application DE 10 2004 017 832 B3 relates to a hearing aid having a housing into which an antenna is integrated as an electrically conducting layer in order to reduce the size of the hearing aid. The antenna may be L-shaped as a metal layer applied to the hearing aid housing, the antenna may be applied as a pre-shaped foil element onto the hearing aid housing, the antenna may be produced by structuring a metal layer of the hearing aid housing or the antenna may be fabricated as a conducting plastics layer during injection moulding of the hearing aid housing.
European Patent Application EP 1 376 760 A2 relates to a folded dipole antenna for transmitting and receiving radio signals in all types of telecommunication systems, in particular for use in base stations of mobile telephone networks. The antenna consists of three portions, namely a central portion fixed to a ground plate, a left portion and a right portion which are angled by 45° to the central portion in such a manner that they form an angle of 90° relative to each other.
European Patent Application EP 1 594 187 A1 relates to a folded laminar antenna which is designed as a slot-loop antenna with a loop-like slot between conducting portions. The antenna consists of three portions, namely a central portion, a right portion and a left portion, with the right and left portions being folded by about 180° onto the central portion. The antenna comprises a layer of electrically conductive material which is provided on a dielectric substrate layer. The antenna may be used in portable wireless devices such as mobile telephones and personal digital assistants.
German Patent Application DE 10 2004 016 573 B3 relates to a binaural In-the-ear (ITE) hearing aid system wherein each of the two hearing aids has an antenna for wireless communication with the other hearing aid and wherein the antenna is oriented at a certain angle with respect to the housing in order to ensure that the two antennas are aligned when the hearing aids are worn by the user.